1. Field of the Invention
The present invention pertains to the closure of flexible packages, such as plastic bags, and in particular to fastener closures employing sliders.
2. Description of the Related Art
With the recent emphasis in providing consumers with bulk quantities of various commodities, such as food products, reclosable packages have become increasingly popular. One of the most popular means of providing reclosability is to employ zippers of various types, particularly zippers which are compatible with flexible packages of plastic film construction. Manufacturers of food products and other commodities are concerned with filling the contents of a flexible package as quickly and economically as possible. It is important that the opening provided by the fastener be made as large as practically possible. Consumers or other end users also prefer large sized openings for easy extraction of products from the package interior. Even with large openings, however, products within the package may interfere with fastener operation when product poured or otherwise dispensed from the package becomes entrained in the fastener components.
Other improvements to flexible reclosable packages are being sought. For example, when handling products comprised of numerous small pieces, such as shredded cheese or cereal, for example, it is generally desirable to have the package formed into a pouch which is open at one end, or along one side, so as to allow product to be poured or shaken through the reclosable opening. It is desirable that the product be allowed to freely flow past the reclosable opening. Preferably, the path taken by the product within the package should be made as smooth as possible.
Although improvements have been made in the art of plastic welding and joining, manufacturers of consumer products employing high speed production techniques are continually seeking improved package forming methods and equipment. Concern has been focused on the formation of stop members which limit the travel of a sliding closure traveling along fastener tracks. Any reduction in the time needed to form these and other package features can result in substantial cost savings.
It is an object of the present invention to provide an improved fastener closure for flexible packages.
Another object of the present invention is to provide reclosable packages having fastener sliders which are protected as the package contents are poured out or otherwise extracted.
A further object of the present invention is to provide a reclosable package having improved arrangements for hanging display.
Yet another object of the present invention is to provide a reclosable plastic package having a slider fastener with improved containment of the slider in a manner which also optimizes the size of the bag opening.
A further object of the present invention is to provide a plastic bag having a slider fastener with an improved end or xe2x80x9ccrushxe2x80x9d seal of the fastener tracks.
These and other objects of the present invention are attained in a reclosable flexible package comprising: opposed front and rear panels having sides and joined together to form an interior and a package opening communicating with said interior;
first and second interlockable fastener tracks configurable in an interlocked, closed position and an unlocked open position;
a slider movable along said fastener tracks to configure said tracks in said interlocked position so as to close said opening and to configure said fastener tracks in said unlocked position so as to allow access through said opening to said package interior;
said fastener tracks having opposed ends located adjacent said opposed sides of said front and said rear panels;
stops adjacent said ends of said fastener tracks to interfere with and prevent travel of said slider beyond said fastener tracks;
a side seal of pre-selected width joining together one side of said front and said rear panels, said side seal having an enlarged end portion of enlarged width adjacent said fastener tracks, with at least a part of said enlarged end portion disposed below said fastener tracks; and
wherein said enlarged end portion is disposed beneath the substantial entirety of said slider and shields said slider, deflecting product being discharged from said package interior, around said slider.
It has been determined that, in a practical commercial environment, it is difficult to employ conduction heat sealing techniques to form the slider stop. It is preferred that the stop be formed using ultrasonic sealing techniques, as these afford greater control over dimension and shape. This is important when the maximum number of advantages accorded the present invention are being sought, since the mass, and particularly the frontal surface area of the stop is reduced to the greatest extent possible.